Brake Swap Master Cylinder
Pascal's law - "a change in the pressure of an enclosed incompressible fluid is conveyed undiminished to every part of the fluid and to the surfaces of its container."
http://www.grc.nasa.gov/WWW/K-12/Wi...hyperphysics.phy-astr.gsu.edu/HBASE/pasc.html
http://en.wikipedia.org/wiki/Hydraulic_brake - A larger diameter master cylinder delivers more hydraulic fluid to the caliper pistons, yet requires more brake pedal force and less brake pedal stroke to achieve a given deceleration. A smaller diameter master cylinder has the opposite effect.
http://hyperphysics.phy-astr.gsu.edu/HBASE/pasc.html#hpcal- 3rd one down - an online calculator, you can plug in some numbers and see that by increasing the MC piston size you loose your force multiplication resulting in more force needed, with a little less distance to accomplish the same goal. IE a little less pedal travel with greater force needed to get the pistons in the calipers to move the same distance. Simply put you have to push harder.
another example
http://science.howstuffworks.com/hydraulic1.htm
To determine the multiplication factor, start by looking at the size of the pistons. Assume that the piston on the left is 2 inches in diameter (1-inch radius), while the piston on the right is 6 inches in diameter (3-inch radius). The area of the two pistons is Pi * r2. The area of the left piston is therefore 3.14, while the area of the piston on the right is 28.26. The piston on the right is 9 times larger than the piston on the left. What that means is that any force applied to the left-hand piston will appear 9 times greater on the right-hand piston. So if you apply a 100-pound downward force to the left piston, a 900-pound upward force will appear on the right.
How brake fluid works
Pressure is the result of a force applied over a specific area and that pressure is therefore measured by the formula P = F / A or "pressure equals force divided by area". When a force is applied to an incompressible fluid, the area in question is the contact area between any two molecules of the fluid. That area is the same for any pair of molecules within the fluid. Because an incompressible fluid accepts and applies forces evenly throughout itself, the pressure will be equal at all points within the fluid. The molecules that are in contact with the surface of the container will push against that surface with the same pressure as between any two molecules anywhere else within the container because they have the same contact area with the molecules of the container as with each other.
If we consider that this container and its fluid contents are subject to gravity as an additional force then we must consider that the difference of pressure due to a difference in elevation within a fluid column is given by:
where
ΔP is the hydrostatic pressure (given in pascals in the SI system), or the difference in pressure at two points within a fluid column, due to the weight of the fluid;
ρ is the fluid density (in kilograms per cubic meter in the SI system);
g is acceleration due to gravity (normally using the sea level acceleration due to Earth's gravity in meters per second squared);
Δh is the height of fluid above the point of measurement, or the difference in elevation between the two points within the fluid column (in meters in SI).
The intuitive explanation of this formula is that the change in pressure between two elevations is due to the weight of the fluid between the elevations.
Note that the variation with height does not depend on any additional pressures. Therefore Pascal's law can be interpreted as saying that any change in pressure applied at any given point of the fluid is transmitted undiminished throughout the fluid.
In conclusion a small bore MC will require a little bit more pedal BUT the force multiplication goes up so it will be easier to stop with more power. A large bore MC will require a little less pedal travel but at the expense of more effort to push the pedal.
Having this set up on my car I highly recommend it and it doesn't seam like I have to push the pedal in very far to stop.
Also with the 73-76 Dart disc and the Valarie disc conversion, you also need the 73-76 Dart upper control arms with the larger ball joint.
And you are correct